1. Field of the Invention
This invention relates to feed control for a brush chipper. More particularly, the invention relates to a method and apparatus for providing a stop position to the forward (or feed), neutral, and reverse positions presently associated with brush chipper mechanical feed bar mechanisms. The hydraulic control valve actuated by the feed bar has three positions: forward (or feed), neutral, and reverse.
2. Background Art
Feed control for a brush chipper presently takes one of two forms: (1) mechanical or (2) electrical. Electrical controls require a functioning source of electrical power such as a generator or battery. Mechanical control systems do not require electrical power, but have proved less versatile than the electrical systems in the past.
The feed wheels in a brush chipper are typically hydraulically driven. The flow of hydraulic fluid is controlled by a hydraulic control valve. Hydraulic control valves of the type used for brush chipper feed control have three positions: (1) forward or feed, (2) neutral, and (3) reverse. Mechanical feed control bars, until now, have been configured only to take advantage of these three positions. An implication of this is that, if the feed mechanism becomes plugged or the chipper bogs down due to a greater feed rate than permissible, the operator must carefully find neutral, then reverse. Usually, neutral is centered between forward and reverse, as this is the way the hydraulic control valve is typically arranged.
An electrically controlled brush chipper is disclosed in U.S. Patent application No. 2004/0108397 entitled Improved Brush Chipper and methods of Operating Same by O'Halloran et al., filed Dec. 1, 2003 and is hereby incorporated by reference. In the disclosed approach, a plurality of operating modes is disclosed using the versatility of electrical/electronic controls.
U.S. Pat. No. 5,692,548 by Bouwers et al. and U.S. Pat. No. 5,692,549 by Eggers are hereby incorporated by reference and disclose brush chippers having many components of the brush chippers on which the present invention is used. Some of the pertinent components are: a material inlet, or feed table assembly, a plurality of feed rollers, and a chipping drum. The feed rollers are driven by hydraulic motors. No control system for the feed rollers is disclosed.
There is, therefore, a need for a method and apparatus for a mechanical feed control bar providing four positions wherein the extreme positions are stop and reverse.